You can view the graphics by opening BOINC Manager, selecting the Tasks tab, then selecting a Task that is currently running and clicking on the button that reads "Show Graphics".

Not all SETI applications have the graphics part included. So, that works only with the CPU applications (AFAIK).

NOTE that the graphics have changed slightly to look more "3D" and wobble back and forth so as to prevent screen burn. There is no way to change the graphics back to the old one you used to see in SETI@home Classic.

Yes, I'd like to run BOINC as a service. Would I have to re-install it to do so?

Yes, but that's a pretty simple affair. You just have to stop the BOINC client and then uninstall BOINC. That's a non-destructive process, so the data is not touched. Install again in service mode and after rebooting, BOINC should start where it's left off.

I already discovered, to my dismay, that logging out of the admin account stops BOINC...

Since you are not using a GPGPU for computing, you could install BOINC as a service (FKA Protected Application Execution). Then BOINC would even run when nobody is logged in. However, you'd still have to prevent windows from hibernating (energy saving settings?).

I find it very complicated to understand which file overrides the other.

It's just that global_prefs_override.xml overrides global_prefs.xml (as can be inferred from the name ;-).

As ageless wrote in the other post, these files are implicated:
"....files cc_config.xml, global_prefs_override.xml, gui_rpc_auth.cfg, and remote_hosts.cfg.."

The file cc_config.xml doesn't have any effect on the preferences, it just sets some options and/or log flags for the core client (cc_config); gui_rpc_auth.cfg and remote_hosts.cfg just enable controlling of remote clients.

and then there's the global settings, with can be set up different between projects.

No, that's wrong. They are called 'global preferences' because they are the same on each of your projects. The actual (newest) set is distributed by BOINC automatically. Only the project preferences (where you can set the resource share for example) and the community preferences can be different from project to project.

And the setup in BOINC Manager (windows) overrides "Global" settings on the account/website/ e.g. SETI/Asteroid

No, the BOINC manager overrides the global preferences only locally on the computer where the changes are made (by creating the file global_prefs_override.xml).

What I really need is a little piece of software or a service on the net, which shows me the status, results, setup, etc. etc.

That software would be the BOINC manager. You even can manage remote hosts with it. You just have to be careful to always 'Cancel' the preferences window if you just wanted to see the preferences. Otherwise the file global_prefs_override.xml is created and all subsequent online changes are overriden/suppressed. If you have accidentally created that file, just delete it or press the 'Clear' button in the preferences window of BOINC manager, which does the same.

However, that wouldn't explain why changing the default setting to 100% did work. That should also be suppressed by the local preferences, unless you meanwhile had deleted the global_prefs_override.xml file.

#1 I'm running linux/ubuntu on my computers and all computers are running the boinc-client only. Therefore I'm using the command line tool "boinccmd" to comunicate with the computers..
Does anyone know a command to check the current CPU time % setup? (e.g. Use at most: 50% of CPU time)

If possible, the command to check the other 2 fields as well.
On multiprocessors, use at most: --- processors
On multiprocessors, use at most: --- % of the processors

AFAIK, there's no command for that, but you can check in global_prefs.xml and global_prefs_override.xml for the <cpu_usage_limit> parameter. The other two are <max_cpus> and <max_ncpus_pct> respectively.